"The actual production of Musicassettes was done on machines running 32 times faster than normal playback. Cassette tape would be reeled over four heads recording what would be both sides at once at 60 IPS. The master tape that was source of the original music had been recorded at 7.5 IPS and this would also run 32 times faster, clocking up a playback speed of 240 IPS for duplication purposes."
"This super-fast tape transport also required the circuitry to follow suit. So instead of the bias frequency being around 80kHz, it was now 2.4MHz; the amplifiers also needed to work over a frequency range of 200kHz to 500kHz."
Commodore 64 with best tape Turbo is able to store slightly above 1MB per cassette. Japan already had floppy drives capable of storing over 1MB in 1983, but it looks like Etak needed more, with this 40 times faster tape drive delivering:
"local map data base stored on a 3.5-MByte tape cassette."
I would love to learn more details about this drive. Modulation used? Number of tracks? Format? Magnetic flux dump of one of the cassettes would be a lovely puzzle to decode.
Tape shown in the video demonstration of Etak was ordinary 1/8 Philips 4 x 2 1/2 x 1/2.
>another source <https://rosap.ntl.bts.gov/view/dot/2332/dot_2332_DS1.pdf>
Dimensions are for a Tape Drive so that matches Philips cassette. Speed is 40x normal, but reading https://www.theregister.com/Print/2013/08/30/50_years_of_the...
"The actual production of Musicassettes was done on machines running 32 times faster than normal playback. Cassette tape would be reeled over four heads recording what would be both sides at once at 60 IPS. The master tape that was source of the original music had been recorded at 7.5 IPS and this would also run 32 times faster, clocking up a playback speed of 240 IPS for duplication purposes."
"This super-fast tape transport also required the circuitry to follow suit. So instead of the bias frequency being around 80kHz, it was now 2.4MHz; the amplifiers also needed to work over a frequency range of 200kHz to 500kHz."
Commodore 64 with best tape Turbo is able to store slightly above 1MB per cassette. Japan already had floppy drives capable of storing over 1MB in 1983, but it looks like Etak needed more, with this 40 times faster tape drive delivering:
"local map data base stored on a 3.5-MByte tape cassette."
I would love to learn more details about this drive. Modulation used? Number of tracks? Format? Magnetic flux dump of one of the cassettes would be a lovely puzzle to decode.